"Coral reefs are shallow-water tropical and subtropical communities, with
exceedingly complex interrelationships among species: they have arguably the
highest species diversity of any marine community.
Their productivity is driven by two main components: symbiotic algae (zooxanthellae)
that live inside reef-building corals, and some other invertebrates and free-living
algae, especially benthic seaweeds.
The growth of the reef structure itself depends upon calcification by corals
and coralline algae, and thus upon adequate light for photosynthesis: they are
therefore sensitive to reductions in light penetration from increased turbidity.
Reefs typically form in oligotrophic waters within a relatively narrow range
of temperature and salinity, and tend to grow in temperatures near the upper
limits of tolerance for the corals that build them.
Thus, reef communities are sensitive to relatively small changes in temperature
and salinity."
Source: GESAMP 71:27
GESAMP (IMO/FAO/UNESCO-IOC/WMO/WHO/IAEA/ UN/UNEP Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection). 2001. Protecting the oceans from land-based activities - Land-based sources and activities affecting the quality and uses of the marine, coastal and associated freshwater environment. Rep. Stud. GESAMP No. 71, 162 pp. ISBN 82-7701-011-7.